Question

我的Xamarin.native项目针对Android＆amp; iOS版。我无法在Xamarin.iOS中显示警报;以下代码适用于Xamarin.Android。

在PCL中：

public interface IDialogProvider
{
    void ShowMessage(string title, string message, string dismissButtonTitle, Action dismissed);
    void Confirm(string title, string message, string okButtonTitle, string dismissButtonTitle, Action confirmed, Action dismissed);
}

======================================

在Xamarin.iOS

public class TouchDialogProvider : IDialogProvider
{
    public void ShowMessage(string title, string message, string dismissButtonTitle, Action dismissed)
    {
        var alert = UIAlertController.Create(title, message, UIAlertControllerStyle.Alert);
        alert.AddAction(UIAlertAction.Create(dismissButtonTitle, UIAlertActionStyle.Default,
        action => { if (null != dismissed) { dismissed.Invoke(); } }));
    }

public void Confirm(string title, string message, string okButtonTitle, string dismissButtonTitle, Action confirmed, Action dismissed)
{
    var alertView = new UIAlertView(title, message, null, dismissButtonTitle, okButtonTitle);
    alertView.Clicked += (object sender, UIButtonEventArgs e) => {
    if (e.ButtonIndex == 1 & null != confirmed)
        { confirmed.Invoke(); }
        if (e.ButtonIndex == 0 & null != dismissed)
            { dismissed.Invoke(); } };
    alertView.Show();
    }
}

Answer 1

您永远不会在ShowMessage方法中展示视图控制器：

public void ShowMessage(string title, string message, string dismissButtonTitle, Action dismissed)
{
    var alert = UIAlertController.Create(title, message, UIAlertControllerStyle.Alert);
    alert.AddAction(UIAlertAction.Create(dismissButtonTitle, UIAlertActionStyle.Default,
    action => { if (null != dismissed) { dismissed.Invoke(); } }));
    var rootVC = UIApplication.SharedApplication.Windows[0].RootViewController;
    rootVC.PresentViewController(alert, true, null);
}

另一个Confirm方法应该从UIAlertView更改为UIAlertController，因为自iOS 9以来已弃用UIAlertView。

Answer 2

请尝试使用以下一项来创建警报，我始终仅使用此一项。

    void CreateAlert(string title, string buttonTitle, RelayCommand buttonCommand, string error, RelayCommand closeButtonCommand = null)
    {
        var elements = new List<InfoDialogElement>{
            new InfoDialogElement
            {
                Type = InfoDialogElementTypeEnum.Text,
                MarginTop = 25,
                MarginBottom = 25,
                SideMargin = 0,
                Info = error,
                TextSize = 16,
                Font = FontStyleEnum.OoredooHeavy
            }
        };
        var dialog = new OoInfoDialog(title, buttonTitle, buttonCommand, elements);
        if (closeButtonCommand != null)
            dialog.CloseCommand = closeButtonCommand;

        if (DialogBeingPresented != null)
            DialogBeingPresented.PresentDialog(dialog, UIColor.FromRGBA(0, 0, 0, 230));
        else
        {
            var parentViewController = AppDelegate.Current.Window.RootViewController;
            if (parentViewController != null)
            {
                if (parentViewController is UINavigationController)
                {
                    (parentViewController as UINavigationController).TopViewController.PresentDialog(dialog, UIColor.FromRGBA(0, 0, 0, 230));
                } else
                {
                    parentViewController.PresentDialog(dialog, UIColor.FromRGBA(0, 0, 0, 230));
                }
            }
        }
    }

Answer 3

将您的AlertView显示为PresentViewController

InvokeOnMainThread(() =>
    {
        var alert = UIAlertController.Create(title, message, UIAlertControllerStyle.Alert);
        alert.AddAction(UIAlertAction.Create(dismissButtonTitle, UIAlertActionStyle.Default, action => { if (null != dismissed) { dismissed.Invoke(); } }));
        PresentViewController(alert, true, null);
    });

Answer 4

我认为有一种更简单的方法来制作警报弹出窗口。你可以这样试试：

UIAlertView alert = new UIAlertView()
{
    Title = "Network error",
    Message = "Please check your internert connection"
};
alert.AddButton("Cancel");
alert.AddButton("OK");
alert.Show();
alert.Clicked += Alert_Clicked;

void Alert_Clicked(object sender, UIButtonEventArgs e)
{
   if(e.ButtonIndex == 1 )
   {
      //your action on alert dialog OK button click
   }
}

Answer 5

 public void ShowMessage(string title, string message, string dismissButtonTitle, Action dismissed)
    {
        //var alert = UIAlertController.Create(title, message, UIAlertControllerStyle.Alert);
        //alert.AddAction(UIAlertAction.Create(dismissButtonTitle, UIAlertActionStyle.Default,
        //         action => { if (null != dismissed) { dismissed.Invoke(); } }));

        //UIApplication.SharedApplication.KeyWindow.RootViewController.PresentViewController(alert, true, null);



        UIAlertController actionSheetAlert = UIAlertController.Create("App!!!", "\n" +
                                             "  " +
                                                                      "1. User Created", UIAlertControllerStyle.Alert);

        actionSheetAlert.AddAction(UIAlertAction.Create("OK", UIAlertActionStyle.Default, action => { if (null != dismissed) { dismissed.Invoke(); } }));

        UIApplication.SharedApplication.KeyWindow.RootViewController.PresentViewController(actionSheetAlert, true, null);
    }

这是我的工作代码

这样称呼

ShowMessage("s", "s", "s", null);

“ s”只是伪文本，一切都在ShowMessage（）中完成

UIAlertView无法正常工作是Xamarin.iOS

在PCL中：

在Xamarin.iOS

5 个答案: